Almost 30,000 people gathered at the 4/20 pro-marijuana rally in Vancouver this year — where a huge variety of marijuana-based “edibles” were available. Sweets, baked goods, beverages, oils, and more were sold throughout the day by dozens of vendors.

One such vendor sold innocuous-looking brownies out of a tent. The effects were not immediate, but after several hours, consumers of this particular product experienced dizziness, heart palpitations, vomiting, and extreme grogginess. One high school student was taken to hospital and many became ill. Ultimately, the negative effects took three full days to wear off completely.

Although the police attributed these effects to THC (the active ingredient in pot), none of these symptoms are characteristic of THC poisoning, suggesting that the brownies may have been laced with another substance.

Since police quickly attributed the effects to marijuana, it is unclear if efforts were made to catch the culprit, who may have intentionally fed a noxious substance to his customers. This case calls into question the safety of edibles and highlights the failure of food safety authorities to provide reasonable oversight for these products.

Marijuana-based infused edibles such as candy bars, cookies, mints, drinks, and brownies have recently been legalized in Colorado and Washington, with many other jurisdictions poised to follow suit. These products provide significant medicinal benefits of medicinal marijuana usage without exposing the lungs to pungent smoke and provide a more refined level of dosage control than other methods (while also taking care of the munchies).

For example, low THC oils are being used to successfully treat very young children with seizures. Many edibles users report longer acting, mellow highs that manage pain with less impact on higher cognitive functions.

The fact that an infused chocolate bar only costs about $3 is another advantage over other methods of consumption. As a result, edibles have become a multi-million dollar industry and products are flying off the shelves faster than they can be produced.

Federal regulatory authorities in Canada and the U.S. cannot police this industry since marijuana edibles remain illegal. This lack of oversight presents a serious public safety concern. The question that we as consumers should be asking is: are these new products safe to eat?

The state of Colorado has addressed this problem by drafting its own regulations and enforcement standards for this industry. In March, Colorado introduced Permanent Retail Marijuana Rules that require food safety training for food handling, sanitation and personal hygiene. This new legislation also defines kitchen standards, and allows for inspections.

Moreover, in order to ensure that edibles are not laced with other chemicals — as was the case at Vancouver’s 4/20 — mandatory testing standards come into force in July and include mandatory testing of the manufacturers cultivation facility.

While these steps are in the right direction, an article last week by Eric Gorsky identified food safety concerns as inspectors have found “raw ingredients that should be kept refrigerated were instead kept out on shelves and that some preparation methods were not sufficient enough to kill food borne pathogens.”

Several manufacturers have been forced to issue recalls for problems such as maintaining storage conditions conducive to the growth of the bacterial spores that cause botulism. Already, more than half of Colorado producers have already had food safety violations, even with some level of regulatory oversight in place.

Currently, regulatory authorities do not play a role in ensuring edibles are safe in Canada since they remain illegal, even for licensed medicinal users. Ironically, this policy increases the likelihood of outbreaks of food-borne illness by driving manufacturers of edibles underground.

The U.S. federal government is not doing much better, leaving regulation to the discretion of individual states to ensure these products are safe, despite the fact that states rely heavily upon the federal food safety programs and inspectors. Blocking these resources puts the health of consumers at risk and, in the absence of regulations, edibles producers are unlikely to adopt advanced food safety standards such as HACCP (hazard analysis and critical control points) and enhance their production processes by introducing HACCP software to ensure their products are safe.

Until the industry receives at least as much attention as other food producers, the safety of edible marijuana products will remain in question.